No. What Carp::cluck does is warns with trace only when you call it. I'm trying to catch the ones that happen from inside the perl VM - such as "use of uninitialized" warnings. What I'd like to do is basically completely mask the warn built-in function with Carp::cluck (assuming that the perl VM calls warn, which is likely to be the case), but the best I can do now is fake it with the __WARN__ handler.

That said, ikegami pointed me along the right path, and I now got this working.